Cloud point analysis: Influence of additives on polysorbate

The solution properties of nonionic surfactants are significantly diverse from those of ionic surfactants. Additives to nonionic surfactant solution do change the cloud point (CP). In this article, we report the CP data of polysorbate 20 (tween-20) and polysorbate 80 (tween-80), nonionic surfactants, in the presence of various additives and also focus on their characteristics. It is observed that the micellization tendency of the polysorbates changes in the presence of different additives. The addition of different variants of salts decreases the CP of polysorbates solutions. Furthermore, the higher the valency of the cation, the lesser is the depression in the CP of the polysorbates. Overall monovalent, di-valent and a mixture of di-valent salts have large affinity to alter the values of CP of polysorbates, because of their effect on the water structure and their hydrophilicity. An effort has been made to understand the influence of various combinations of salts on polysorbates.